Freeze-fracture Studies of Reactive Myelinated Nerve Fibres After Diffuse Axonal Injury

Acta Neuropathol. 1988;76(4):395-406. doi: 10.1007/BF00686977.

Abstract

We have studied the axonal and myelin sheath response in diffuse axonal injury after angular acceleration using the freeze-fracture and thin section techniques. It was found that the glial-axonal junction was intact until 1 h after injury. But upon loss of the nodal axolemma specialisations, after 3 to 4 h, the dimeric particles of the glial-axonal junction (GAJ) were lost and, by 6 h, the myelin lamellae became separated from the axonal remnant. There was a correlated loss of glial membrane specialisations of the GAJ during this separation. In the internodal region a suggestion of membrane damage occurred after 20 min but discrete myelin dislocations (particle-free areas) were not found until 1-h survival and were extensive by 6 h. Areas of loosely organised myelin occurred between intact axons at 7-28 days after injury. No evidence for growth cone formation was obtained.

MeSH terms

  • Animals
  • Brain Injuries / pathology*
  • Brain Injuries / physiopathology
  • Freeze Fracturing
  • Microscopy, Electron
  • Myelin Sheath / ultrastructure*
  • Nerve Fibers, Myelinated / ultrastructure*
  • Papio
  • Time Factors